U2 Glider Conversion Scratch Build Questions

cactus · Feb 06, 2002, 12:16 AM

After reading the Ezone article on the conversion of the Lanier U2 free-flight glider to RC the wheels started turning in my head....

I have been wanting to try sailplanes simply because of the relax factor of soaring around several hundred feet up for 30 mins or more. As a big fan of the Lockheed U2 and the photo missions it under took, I would like to build a low-cost air-born photo or video sailplane modeled after this plane.

The ezone article conversion came out with a 6.4 Sq In wing load using what appeared to be a Zagi 400 power system with standard size (2 servos) radio gear.

The specs are:
Span: 74"
Length: 56"
Wing Area: 4.37 Sq Ft (629 Sq In)
Weight: 16 to 24 Oz (From Lanier)

What would be an acceptable AUW (with camera/wireless payload) and wing loading to produce glider like performance and possibly soar if conditions are right?

What wing loading makes a good floater?

What is the formula to detrumine how much torque from a servo you need to move a control surface? I would like to go as light and as cheap as I can, so would HS-81's be ok?

I just want it to be able to climb to altitude and be able to SLOWLY cruise around and take pictures. No loops, no rolls, just RELAX!

I have only flown aileron and delta mixing type aircraft. Should I bother to put a single servo on the wings to control banking better? I use a JR 8103. Will soom kind of mixing be required if I use only rudder/elevator/throttle?

Mike

Vinnya42 · Feb 07, 2002, 04:51 PM

If you put in 3 HS 81's and standard gear the wing load would be right at 7oz per sq ft. That is pretty good for a glider, but I have a scratch built 8ft fox with a 10 oz wing load and it floats like a dream.
You calculate wing load by dividing weight by sq ft wing area. I would put in 2 degrees of dihaderal in the wing and if the CG is back to far I would cut the fuselage behind the wing it help balance it.

I mainly slope but this looks like a great plane to convert and if I didn't already have 10 planes I would buy it (I might anyway?). the 4.5ft planes they also sell might be fun for 5 bucks.

cactus · Feb 07, 2002, 05:20 PM

Thanks Vinnya42, I thought the HS-81's would work out ok. I prob will use a single servo to add aileron control for those banked aerial shots

I am going to set up everything in MotorCalc and explore my options on power and batteries to try and get 15 min runs at altitude.

When you talk about adding 2 degrees of dihaderal, I assume you mean put an angled shim in-between the wing halfs when I join them? Sounds pretty basic. I should be able to dial in the CG considering I will prob have the camera pod near the front of the plane. I am thinking that I will come in under the review weight, if I use HS-81's and my Jr 610M rx, not including aerial sensor gear.

I was thinking of using a speed 400 motor and an esc with a brake along with a folding cam prop. Would I benifit greatly by using a brake and folding prop?

To Keep the weight down, I prob will not cover it with UltraCoat Plus this time like I have done on my past foam planes. Prob will just do some simple trim work to increase my sense of it's orientation at altitude. Maybe a NASA logo and a few stripes

Mike

Roger_One · Feb 11, 2002, 04:07 PM

Cactus,

Visit www.eam.net look in their "skunkworks" section for the Dragon Lady. I think you'll like it!

cactus · Feb 11, 2002, 09:14 PM

Roger_One, I looked at EAM Dragonlady last fall, but it seems they are still months away from shipping even the eval kits. It sure looks sweet though. I'm not sure I want that much speed....

Mike

cactus · Feb 11, 2002, 09:25 PM

Thanks for all of the input, but I think I am going to scratch the idea of this plane for practicality reasons.... It will be to light to fly in most of the windy days we have here and will require a large field to really enjoy, which means I will prob only fly it twice a month...not worth it for me.

Mike

longshank · Feb 14, 2002, 08:10 AM

Where did you find that article on the u2 modification?
Do you have the Link?

Feb 06, 2002, 12:16 AM	#1
cactus Registered User Join Date: Sep 2001 Location: Durango Colorado Posts: 2,931	U2 Glider Conversion Scratch Build Questions After reading the Ezone article on the conversion of the Lanier U2 free-flight glider to RC the wheels started turning in my head.... I have been wanting to try sailplanes simply because of the relax factor of soaring around several hundred feet up for 30 mins or more. As a big fan of the Lockheed U2 and the photo missions it under took, I would like to build a low-cost air-born photo or video sailplane modeled after this plane. The ezone article conversion came out with a 6.4 Sq In wing load using what appeared to be a Zagi 400 power system with standard size (2 servos) radio gear. The specs are: Span: 74" Length: 56" Wing Area: 4.37 Sq Ft (629 Sq In) Weight: 16 to 24 Oz (From Lanier) What would be an acceptable AUW (with camera/wireless payload) and wing loading to produce glider like performance and possibly soar if conditions are right? What wing loading makes a good floater? What is the formula to detrumine how much torque from a servo you need to move a control surface? I would like to go as light and as cheap as I can, so would HS-81's be ok? I just want it to be able to climb to altitude and be able to SLOWLY cruise around and take pictures. No loops, no rolls, just RELAX! I have only flown aileron and delta mixing type aircraft. Should I bother to put a single servo on the wings to control banking better? I use a JR 8103. Will soom kind of mixing be required if I use only rudder/elevator/throttle? Mike

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Feb 07, 2002, 04:51 PM	#2
Vinnya42 Lifes 2 short, go sloping Join Date: Sep 2001 Location: colorado @ 5500feet Posts: 1,036	If you put in 3 HS 81's and standard gear the wing load would be right at 7oz per sq ft. That is pretty good for a glider, but I have a scratch built 8ft fox with a 10 oz wing load and it floats like a dream. You calculate wing load by dividing weight by sq ft wing area. I would put in 2 degrees of dihaderal in the wing and if the CG is back to far I would cut the fuselage behind the wing it help balance it. I mainly slope but this looks like a great plane to convert and if I didn't already have 10 planes I would buy it (I might anyway?). the 4.5ft planes they also sell might be fun for 5 bucks.

Feb 07, 2002, 05:20 PM	#3
cactus Registered User Join Date: Sep 2001 Location: Durango Colorado Posts: 2,931	Thanks Vinnya42, I thought the HS-81's would work out ok. I prob will use a single servo to add aileron control for those banked aerial shots I am going to set up everything in MotorCalc and explore my options on power and batteries to try and get 15 min runs at altitude. When you talk about adding 2 degrees of dihaderal, I assume you mean put an angled shim in-between the wing halfs when I join them? Sounds pretty basic. I should be able to dial in the CG considering I will prob have the camera pod near the front of the plane. I am thinking that I will come in under the review weight, if I use HS-81's and my Jr 610M rx, not including aerial sensor gear. I was thinking of using a speed 400 motor and an esc with a brake along with a folding cam prop. Would I benifit greatly by using a brake and folding prop? To Keep the weight down, I prob will not cover it with UltraCoat Plus this time like I have done on my past foam planes. Prob will just do some simple trim work to increase my sense of it's orientation at altitude. Maybe a NASA logo and a few stripes Mike

Feb 11, 2002, 04:07 PM	#4
Roger_One Registered User Join Date: Dec 2001 Location: Seguin, Texas Posts: 45	Cactus, Visit www.eam.net look in their "skunkworks" section for the Dragon Lady. I think you'll like it!

Feb 11, 2002, 09:14 PM	#5
cactus Registered User Join Date: Sep 2001 Location: Durango Colorado Posts: 2,931	Roger_One, I looked at EAM Dragonlady last fall, but it seems they are still months away from shipping even the eval kits. It sure looks sweet though. I'm not sure I want that much speed.... Mike

Feb 11, 2002, 09:25 PM	#6
cactus Registered User Join Date: Sep 2001 Location: Durango Colorado Posts: 2,931	Thanks for all of the input, but I think I am going to scratch the idea of this plane for practicality reasons.... It will be to light to fly in most of the windy days we have here and will require a large field to really enjoy, which means I will prob only fly it twice a month...not worth it for me. Mike

Feb 14, 2002, 08:10 AM	#7
longshank Registered User Join Date: Feb 2002 Location: Tallahassee, Fl Posts: 6	Where did you find that article on the u2 modification? Do you have the Link?